Flexible ligands-dependent formation of a new column layered MOF possess 1D channel and effective separation performance for CO2.

A new column layered MOF with (3,6)-connected nets, namely [Co(pysa)(H 2 O)] n (YAU-7), was synthesized by using Co(NO 3) 2 ·6H 2 O and organic ligand 2-(pyrid-4′-yl)-benzimidazole-5-carboxylic acid (H 2 pysa) as flexible linkers. Single-crystal X-ray diffraction evidences the 3D YAU-7 MOF with (3,6)-connected nodes, a binuclear cluster [Co 2 (COO) 2 ] structure and 1D tunnel feature. The weak interactions of π---π stacking enhances chemical stability of YAU-7 3D structure. Interestingly, the YAU-7 presents high chemical/thermodynamic stability, superior adsorption performance for CO 2 , CH 4 , C 2 H 2 and C 2 H 4 , and high IAST selectivities for mixed gas systems of C 2 H 2 /CO 2 , C 2 H 4 /CO 2 , and CH 4 /CO 2 (50/50). In contrast, YAU-7 exhibits higher uptake of CO 2 (55.70 ​cm3 ​g−1) compared with CH 4 , C 2 H 2 , and C 2 H 4 (27.39, 23.36, and 9.04 ​cm3 ​g−1) at 273 ​K. YAU-7 takes separation values for C 2 H 2 /CO 2 , C 2 H 4 /CO 2 , and CH 4 /CO 2 mixture (37.6, 22.7, and 31.2) significantly higher than the C 2 H 2 /C 2 H 4 , C 2 H 2 /CH 4 , C 2 H 2 /CO 2 , C 2 H 4 /CH 4 mixture gas (1.30, 1.83, 1.67). The YAU-7 MOF is a promising material for CO 2 separation under ambient conditions. Mesoporous MOFs modified by 1D channels and column layer structure have been designed and synthesized as adsorption materials with excellent adsorption and separation properties. Image 1 • Design and prepare mesoporous MOF materials. • Column layer MOF possess 1D channel with dimensionality of 8.583 ​Å ​× ​12.593 ​Å. • YAU-7 MOF with excellent gas separation properties. [ABSTRACT FROM AUTHOR]